#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef double db;

#define in read()
#define pii pair<int,int>
#define fi first
#define se second
#define FILE(x) freopen(x".in","r",stdin);\
	freopen(x".out","w",stdout);
#define pb push_back

int read(){
	int x = 0,sgn = 1;char ch = getchar();
	for(;!isdigit(ch);ch = getchar()) if(ch == '-') sgn = -1;
	for(;isdigit(ch);ch = getchar()) x = (x<<1)+(x<<3)+(ch^48);
	return x*sgn;
}

const int N = 810;
const int inf = 0x3f3f3f3f;

int h[N],cnt=1,D,n,m,hi[22][22],num[2][22][22],nodenum,S,T,d[N],now[N],maxflow;
char s[22];
vector<int> have;
struct edge{int v,w,nxt;}e[N*N];
void link(int x,int y,int w){e[++cnt] = (edge){y,w,h[x]};h[x] = cnt;e[++cnt] = (edge){x,0,h[y]};h[y] = cnt;}

bool bfs(){
	queue<int> q;q.push(S); memset(d,0,sizeof(d)); d[S] = 1; now[S] = h[S];
	while(q.size()){
		int x = q.front(); q.pop();
		for(int i = h[x],y;i;i = e[i].nxt){
			if(!d[y = e[i].v] && e[i].w){
				now[y] = h[y];d[y] = d[x] + 1;
				q.push(y); if(y == T) return 1;
			}
		}
	}return 0;
}

int dfs(int x,int flow){
	if(x == T) return flow;
	int res = flow;
	for(int i = now[x],y;i && res;i=e[i].nxt){
		now[x] = i;
		if(d[y = e[i].v] == d[x] + 1 && e[i].w){
			int k = dfs(y,min(e[i].w,res));
			if(!k) d[y] = 0; res -= k; e[i].w -= k; e[i^1].w += k;
		}
	}return flow - res;
}

int main (){
#ifndef ONLINE_JUDGE
	freopen("1.in","r",stdin);
#endif
	n = in,m = in,D = in;S = 0;int tot = 0;
	for(int i = 1;i <= n;i++)
		for(int j = 1;j <= m;j++){
			scanf("%1d",&hi[i][j]);
			if(hi[i][j]) num[0][i][j] = ++nodenum,num[1][i][j] = ++nodenum,link(nodenum-1,nodenum,hi[i][j]);
		}
	T = ++nodenum;
	for(int i = 1;i <= n;i++){
		scanf("%s",s+1);
		for(int j = 1;j <= m;j++) if(s[j] == 'L' && hi[i][j]) have.pb(num[0][i][j]),tot++;
	}
	for(int x : have) link(S,x,1);
	for(int i = 1;i <= n;i++)
		for(int j = 1;j <= m;j++)
			if(num[1][i][j])
				for(int x = 1;x <= n;x++)
					for(int y = 1;y <= m;y++)
						if(num[0][x][y] && (i != x || j != y)){
							if((i - x) * (i - x) + (j - y) * (j - y) <= D * D)
								link(num[1][i][j],num[0][x][y],inf);
						}
	for(int i = 1;i <= n;i++)
		for(int j = 1;j <= m;j++)
			if(num[1][i][j])
				if(i <= D || j <= D || i + D > n || j + D > m) link(num[1][i][j],T,inf);
	int flow = 0;
	while(bfs()) while(flow = dfs(S,inf)) maxflow += flow;
	printf("%d\n",tot-maxflow);
	return 0;
}
